Remote control system



Nov. 22, 1932.

H. E. HERSHEY REMOTE CONTROL SYSTEM File'd May 5, 1928 2 Sheets-Sheet 1Nov. 22, 1932. H. E. HERSHEY REMOTE CONTROL SYSTEM Filed may 5, E1928 2Sheets-Sheet 2 A27 A WAY Y' 1% Han" E. Her she Patented Nov. 22, 1932UNITED STATES PATENT OFFICE HARRY E. HERSHEY, OF OAK PARK, ILLINOIS,ASSIGNOR, BY MESNE ASSIGNMENTS,

TO ASSOCIATED ELECTRIC LABORATORIES, INC., OF CHICAGO, ILLINOIS, ACORPORA- TION OF DELAWARE Application filed May 5, 1928. Serial No.275,304.

This invention relates in general to remote control systems, moreparticularly to such systems in which a plurality of selecting switcheslocated in distant substations are opera-ted synchronously from acentral or despatohers station, and the principal object of theinvention, briefly stated, is the production of a new and improvedsystem of this type, a system particularly adaptable for use in traindespatching systems.

Tandem type remote control systems have been devised heretofore, and insuch systems in which a step-by-step switch is used as a selector it hasbeen standard practice to bring all of these selectors to rest upon aparticular set of contacts to select a particular device, which is thenoperated and supervised before the selector switches are stepped on tothe next contact set. Systems of this type have their greatest utilityin the remote control of power switching equipment. In the remotecontrol of railway equipment, it is disadvantageous to bring theselecting switches to rest prior to the operating of a particulardevice. In train despatching systems, it is preferable to operate thetrack side devices without stopping the selecting switches. Step-by-stepswitches are not designed for continuous operation, it being customaryto provide a normal or home position in which the switches come to restwhen not in use.

As a further object of my invention, I have provided a new and improvedtrain despatching system of the semi-continuous type, in whichstep-by-step selecting switches are resting in a home position when notin use, and are stepped completely over their banks back to the homeposition without stopping when taken for use. During the stepping of theswitches, one or more of the devices selectable by the switches may beoperated, and all of. the devices are super- 4 vised.

In train despatching practice, a three-position relay, responsive tocurrent in one 01' the other directions or to no current at all, is usedto control the motor-driven semaphores, switches, and the like. Theserelays are controlled by a manual switch having three positions, theswitch being arranged to transmit current of one polarity to the relaywhen in one position, and to transmit current of the opposite polaritywhen in another position, and to transmit no current when in the thirdposition. In equipping a system of this kind for remote controloperation by a centralized despatchers station, it is necessary toprovide a system capable of transmite ting current in either directionor no current to this existing three-position relay.

Accordingly, as a further object of my invention, I have provided a newand improved remote control system capable of transmit- 5 ting currentin either direction or no current at all to an existing three-positionswitch control relay.

Train despatching systems in. use at the present time employ a stationselector to ring 7 the call bells of a particular station, which uponresponding is thrown on to a common talking circuit over whichtelephoneconversation may be had with the despatcher. In many instances, it isdesirable, although not necessary, to maintain this service, and toequip the remote control system over which the switching devices arecontrolled so that the despatcher may call an attendant at any one ofthe substations on the trunk line.

Further objects of my invention, not specifically mentioned here, willbe apparent from a reading of the detailed description and claims whichfollow.

The drawings comprising Figs. 1, 2, 3, and 4 when arranged with Fig. 2to the right of Fig. 1 with correspondingly numbered lines in alignment,show sufficient details of one embodiment of my invention to enable aclear understanding of it, while Figs. 3 and 4 show a detailed side viewand a front view of the mechanical construction of the electro polarizedrelay shown in Fig. 2. This embodiment, designed to meet particularrequirements, is shown by way of example only, as there are manymodifications and adaptations which can be made by one skilled in theart.

Fig. 1 shows the equipment at the despatchers station. The equipment inthe despatchers station comprises the key shelf conta ning keys K to K3,inclusive. Key K is associated with one circuit, K1 with another, etc.,there being a key of this type for each of the circuits controlled fromthis station. Keys K2 and K3 are special operating keys, the purpose ofwhich will be brought out in detall hereinafter. The despatchers stationis also ui ped with a stepping switch S, which 1s the type of thewell-known rotary line switch whose wipers are moved when the magnetdeenergizes. This switch contains a bank having twenty-five contacts marow. The despatchers station also comprises relays 5 to 14, inclusive,through the operation of which the devices at the substation arecontrolled and supervised. In Fig. 1, I also show train despatchingkeyboard TI), which may be of the type shown in my co-pendmg applicationSerial No. 236,301, filed November 28, 1927, or it may be a key senderof the type employed in the well-known \Vestern Electric traindespatching system.

In Fig. 2, I show the equipment in two substations, the one includingselecting switch S1 being shown in full and the other including theselecting switch S2 being shown in skeleton form only. The varioussubstations on the trunk are duplicates of each other, and it is notdeemed necessary to show more than one of these in any great detail. Theselecting switches S1 and S2 are mechanically similar to the switch S ofthe despatchers station, and are moved in synchronism with the switch Sto rotate their wipers over their banks to connect up the substationdevices simultaneously with the connecting up of the supervisory devicesby the switch S. The circuit arrangement for stepping the switches insynchronism is disclosed and claimed in my co-pending application,Serial No. 275,027, filed May 4, 1928. The upper part of Fig. 2 may showa three-position switch control relay 101, which is shown as a simplepolarized relay. This relay would preferably be an existingthree-position control relay in a train despatching system, the relaywhich is energized by the operation of the system under the control ofthe despatcher. A second polarized relay, comprising the energizingwinding 103 and the operating windings 102 and 102, is associated with aparticular bank contact in the bank of switch S1 and operated by thedespatcher to control the application or non-application of current tothe control relay 101. The iron cores of windings 102 and 102 aremagnetically connected at one end by a heel piece which is alsomagnetically connected to the core of windin g 103. The armature of therelay is pivoted over the cores of windings 102 and 102 on the magneticmember extending from the core of winding 103. This latter polarizedrelay takes the place of the manual three-position key or lever withwhich the tower man now controls the control lever or relay 101 in atrain despatching system. A diagrammatic design of this relay is shownin Figs. 3 and 4, showing how the magnets 102, 102', and 103 andarmature 137 are mounted.

Associated with the polarized relay 102 is an alternating current relay104 which is operated under certain conditions to control the operationof the polarized relay 102.

Relay 112 is also a switch control relay, and it in turn is controlledby polarized relay 108 and the alternating current relay 110. Thisequipment is duplicate of the relays 101, 102, and 104, and need not beexplained in greater detail at this time.

The track relay 111 and the associated re-.

lays 105, 106, and 107 are utilized to report to the despatcher themovement of a train hrough the block or siding containing the trackrelay. Relay 111 may be any wellknown track circuit relay such as iscommonly found in railway signalling practice.

Each substation on the trunk line is equipped with a train despatchingselector such as TD1 and TD2, these selectors being either of the typeshown in the aforementioned co-pending application or the wellknownlVestern Electric train despatching selector.

In each substation and in the despatchers station is a battery,preferably a storage battery, having a terminal voltage of about 110volts. The mid-point of this battery is connected to the neutral bus-barN and to the common conductor 7 3 extending between stations. The onehalf of the battery terminates on the negative bus-bar, which is atabout volts potential below the neutral bus.

The other half of the battery terminates on the positive bus-bar, whichis about 55 volts above the neutral bus. On the drawings the neutral busis indicated by an N within a circle, the positive by a plus sign withina circle, and the negative by a minus sign within a circle. This showingeliminates a lot of unnecessary commons and simplifies the drawingsconsiderably.

In the system shown in the drawings, which is a specific embodiment ofmy invention designed to meet the requirements at a particular location,the following results are accomplished:

In this particular embodiment, the selecting switches when once startedout of their normal position continue stepping at a uniform rate untilthe wipers have been brought into engagement with each of their contactsand their banks, at which time the wipers are back in their normalposition where they remain. The devices to be selected, operated, andsupervised are operated during the stepping of the switches, thecircuits being arranged so that the device can be operated during theinterval that the switch remains upon a particular contact, the intervalduring which the other switches of the train are making preparations totake a step. The control relays 101, 112, etc., are employed to controla motor-driven railway switch and the semaphores or lamp signalsassociated therewith. In this particular embodiment, it was not desiredto include any supervision of the operation of the railway switches andsignals; since the signals were lamps, their operation could be reliedupon as long as the elements remained intact, and in case of aburned-out lamp and the resulting dark semaphore, the trainmen are underorders to stop and report to the despatcher. Moreover. in thisparticular embodiment, the movement of the trains on the main line isnot reported to the despatcher, and the track relay 111 is associatedwith a siding to report to the despatcher the occupied or non-occupiedcondition of the siding. In this particular embodiment of the invention,the main line is protected by an automatic block system, over which thedespatcher need exercise no supervision, and his attention is directedto the passing tracks and siding.

This particular embodiment of my invention is shown by way of exampleonly, and obviously the track relay 111 could be in the main linecircuit as in the siding circuit, and the supervisory control exercisedby this track relay could also be applied to the semaphore and trackswitch, if desired, so that the despatcher could be advised of thesuccessful operation of these devices.

If the despatcher desires to operate polarized relay 101 to control aswitching device, he throws the key K to the position shown in thedrawings and energizes the relay 2. Operation of the key K momentarilybreaks the chain circuit over which relay 7 is energized, permittingthat relay to fall back to start the switches b, S1, S2, etc., steppingover their bank contacts. \Vhen wiper 36 engages its fifth workingcontact, it encounters positive potential placed on there through theenergized relay 2, and since wiper 130 is simultaneously resting on itsfifth bank contact, a circuit is completed through the operatingwindings 102 and 102' of the polar relay 102, operating that relay intothe position shown in the drawings. Operation of relay 102 closescircuit for the relay 101 in such a direction that that relay operatesinto the position shown in the drawings. In this position, relay 101controls this associated device over circuits, not shown, to cause it toassume a particular position. The stepping switches 51 and S2 continuestepping over their banks, wipers on coming into engage.- ment withtheir sixth bank contacts select circuit of relay 108 and its associatedcontrolling key K1, so that relay 108 is operated in a directiondepending upon the position of the key Kl. When the wipers have beenpositioned on their seventh bank contacts, the circuit of the polarizedrelay 6 is extended through to the control contacts of the relays 105 to10?, inclusive, and the polarized relay 6 is energized in one directionor another depending upon the energized or deenergized position of thetrack relay 111. Similarly, each of the other contacts in the banks ofthe switches are connected either to control relays or to supervisoryrelays, which are supervised as the wipers pass over them. Theseconnections are not shown, because their inclusion would lead tounnecessary complication of the drawings, since it Will be readilyappreciated that these connections may be identical with those shown inconnection with bank contacts 5, 6, and 7.

From the foregoing, it will be apparent that when wiper 36 picks uppositive battery, the polarized relay will be energized to one position;when it picks up negative battery it will be energized to the oppositeposition. It. is also necessary in a system of this kind to providearrangement for a third or neutral position of the polarized relay. Toaccomplish this purpose, the circuits are arranged so that when thecontrolling key K for example, "s in its neutral position, both positiveand negative direct currents are removed from the bank contacts engagedby wiper 36, and a suitable source of alternating current, say 110 volts(30 cycles, is substituted therefor. The polarized relays in thesubstation areof the magnetically locking type, whose armaturcs remainin the position last set when the current through the coils is removed.Responsive to the recci pt of alternating current over the controlconductor, an alternating current relay is energized to open the circuitof the polarizing winding of these polarized relays, that winding beingsubstituted for the usual permanent magnet such as shown in Patent No.1,672,976, issued June 12, 1928 to F. C. Field with which most polarizedrelays are equipped. Responsive to the deenergization of the polarizingwinding, 103 for example, the polarized relay 102 releases its armaturewhich moves to its central position. In this position, the circuit ofrelay 101 is opened, that relay being of the type which restores to aneutral position when the current flow through its coil is eliminated,assumes its neutral position. By this arrangement, it is possible toobtain three-position operation of the polarized relay 101 and tocontrol operation over one contact in the bank of a selecting switchwhich contact is connected to the des atchers station over a singlewire.

aving thus described my invention in general, I will now proceed with adetailed description of itsoperation.

Assume now that the despatcher desires to control the relay 101 and thathe throws the ke K to the position shown in the drawing? Responsive tothe throwing of the key relay 2 is energized over a circuit from neutralthrough springs 20 to extend a circuit from positive through springs 31and the conductor 61 to the fifth. working bank contact over which wiper36 travels. This prepares a circuit which will be subsequently closed tocontrol the relay 101. The operation of key K, at springs 21,momentarily breaks the chain circuit extending from neutral throughsprings 21, 22, conductor 60, springs 25, springs 26, conductor 60,through springs 39, through the winding of the relay 7 to negative,permitting the relay 7 to deenergize. Relay 7 at springs 40 closes acircuit from neutral through the winding of relay 8, springs 45, thewinding of relay 10, to negative. Relays 8 and 10 energize in thiscircuit. relay 8 locking itself from neutral throu h springs 44, inseries with the relay 1U. Relay 8 at springs 43 closes a circuit fromthe chain conductor through the winding of the relay 7 to negative,energizing the relay 7, which locks itself through springs 39independently of the relay 8.

Relay 10 at springs 48 closes a circuit from neutral through springs 46.through the winding of relay 11 to negative, energizing the relay 11.Relay 11 at springs 42 causes an alarm circuit to sound the alarm untilthe switch S has stepped out of its normal position. At springs 49,relay 1O closes the circuit which is traceable from negative throughresistance 65, springs 51 and its break contact,

springs 49, springs 55, conductor 71. through the winding of relay 115,spring 154 and its break contact, through resistance 123 to positivebattery. Relay energizes over this circuit, and at springs 151 closescircuit from neutral through the winding of motor magnet 113 tonegative, energizing the motor magnet 113. The wipers of the switch S1are not advanced when the magnet 113 energizes, but the armature engagesin ratchet so that the wipers will be advanced when the magnetdeenergizcs and the armature is retracted. Magnet 113 upon energizingcloses circuit for relay 114 at springs 150, energizing relay 114. Acircuit may may now be traced from positive through resistance 123,conductor 174. spring and its break contact. springs 153, through thewinding of relay 119, spring and its break contact,

through the resistance 122 to negative. Line relay 119, which is theline relay of the next substation on the trunk line, is energized overthis circuit. If there are intervening substations between theintermedate substation S1 and the last substation S2, the relaycorresponding to 119 will be energized in the substation adjacent to S1.As many substations as are desired can be added in the switch train,care being taken so that when spring 155 is in its normal position andprojecting positive battery out over the trunk wire, the spring 160 ofthe next substation must lead to negative battery so that the circuit ofthe line relay 119 will be complete.

Relay 119 upon energizing closes a circuit for the motor magnet 117,which energizes preparatory to advancing the wipers of S2 one step andto close the circuit of relay 118 at springs 156. Relay 118 energizes,closing at springs 158 a circuit traceable from negative throughresistance 122, spring 161 and its break contact, through choke coil125, springs 158, conductor 72, through the winding of relay 13 at thedespatchers station, spring 52 and its break contact, through theresistance 66, to positive. Relay 13 energizes over this circuit andcloses a circuit for the motor magnet 15 at springs 53. The motor magnet15 energizes preparatory to advancing the wipers of the switch S onestep and to close the circuit for the relay 14 at springs 50. Relay 14energizes, and at springs 55 opens the circuit over which line relay 115of the intermediate substation was energized. WVhen relay 115 fallsback, it opens the circuit of the motor magnet 113, which falls back andadvances the wipers 130 and 131 of the switch S1 one step. Thedeenergization of the magnet 113 opens the circuit of relay 114, whichfalls back and at springs 153 opens a point in the circuit over whichline relay 119 of the next substation was energized. When relay 119falls back, it opens the circuit of motor magnet 117 to permit thatmagnet to deenergize and advance the wipers 132 and 133 of the switch S2one step and to deener gize the relay 118. Relay 118 opens the circuitof the relay 13 at the despatchers station, permitting that relay tofall back and open the circuit of the motor magnet 15 to advance thewipers 36 and 37 of the switch S one step and to open the circuit ofrelay 14. Relay 14 falls back and prepares a point in the circuit ofrelay 15 at springs 55. prepares a point in the control or supervisorycircuit at springs 54. Since in the drawings the first bank contactengaged by the wiper 36 of the switch S is not shown connected to acontrol relay, description of the operation of the control andsupervisory circuit will be made subsequently.

Viper 37 upon moving to its first working bank contact closes a circuitfrom neutral through that contact, through the winding of relay 12,energizing the relay 12. Wiper 37 upon moving away from its normalcontacts opens a circuit of relay 9, permitting that relay to fall backand at spring 45 break a locking circuit over which relays 8 and 10 weremaintained energized. These relays restore, relay opening a circuit ofrelay 11 to silence the alarm, and relay 8 opening the energizingcircuit over which relay 7 was energized. Relay 9 at springs 47 closes a10 point in the impulsing circuit in lieu of the circuit closed throughsprings 49 of the relay 10. Line relay 115 is now energized over acircuit traceable from positive battery through resistance 66, spring 51and its make contact, springs 47, springs 55, conductor 71, relay 115,spring 154 and its make contact, through the resistance 124 to negativebattery. When the switch S1 is stepped to its first working contact,wiper 131 closes a circuit through the relay 116 to energize that relay,and wiper 133 of the switch S2 closes a circuit for relay 120 when S2steps into engagement with its first working bank contact. Line relay115 energizes over this circuit, closing circuit of motor magnet, whichagain closes circuit of relay 114 to complete the circuit of relay 119,which is now traceable from negative battery through resistance 124,conductor 175, springs 155, springs 153, relay 119, spring 160 and itsmake contact, through resistance 121 to positive battery. Relay 119closes a circuit of the motor magnet, which energizes and closes acircuit of relay 118, which operates and again closes a circuit of therelay 13, the circuit now being traceable from positive battery throughresistance 121, springs 161 and its make contact, the choke coil,springs 158, conductor 72, through the winding of relay 13, throughsprings 52 and its make contact, resistance 65, to negativebattery. Theenergization of relay 13 again closes the circuit of motor magnet, whichenergizes and closes circuit of relay 14, which energizes and opens acircuit of relay 115 as before, and an other impulse is transmittedfirst to the switch S1, then to each succeeding switch until S2 ismoved, then back to the switch S. When the wipers 37, 131, and 133engage their respective second working contacts, relays 12,- 116, and120 are deenergized and the third impulse to be transmitted istransmitted over the circuit traced in connection with the firstimpulse.

Thus it will be seen that the switches S, S1 and S2 are stepped, eachdepending upon the preceding switch both energizing and deenergizing,and moreover the polarity of the pulse sent over the trunk line betweenswitches is reversed on each step. When five steps have been taken,wipers 36, 130, and 132 are resting on their respective fifth workingbank contacts, wiper 130 engages relay 102. Wiper 132 engages an opencontact and need not be considered. Since the relay 2 is C5 energized,and positive battery is placed upon the fifth working contact engaged bywiper 36, as soon as the relay 14 and the relay 114 restore, a. circuitmay be traced from this positive battery and wiper through springs 54,conductor 70, springs 152, wiper 130 and its fifth working contact,through the windings 102 and 102 of the polar relay 102 to neutral,energizing the polar relay which operates its armature 137 in thedirection to move the spring 136 against its right-hand contact, theposition in which it is shown on the drawing. A circuit from the lowvoltage local battery is now completed from the positive pole of thebattery through spring 136 and its make contact, the winding of relay101, spring 135 and its break contact, to the negative pole of battery.Relay 101 is energized over this circuit, its armature being moved intothe position in which itis shown on the drawings, and the local controlcircuits of the track siding device, not shown, are closed by thesprings engaging armature 134.

If the despatcher had thrown the key K to close springs 22 and 23instead of 20 and 21, relay 1 would have been energized and relay 2would have been dcenergized. This operation would have connectednegative battery through springs 29 and conductor 61 to the fifth bankcontact, so that relay 102 would have been energized in the oppositedirection over the circuit just traced, armature 137 would have closedsprings 136 and opened springs 135, thereby connecting the local batteryto the polar relay 101 in the opposite direction, to operate that polarrelay into the position opposite that in which it is shown on thedrawings.

If the despatcher operates the key K to its middle position, so thatboth springs 20 and 21 and 22 and 23 are resting against theirrespective break contacts, neither relay 1 nor relay 2 will beenergized. WVhen wiper 36 engages its fifth working bank contact, itwill complete a circuit from neutral through the alternating currentgenerator 67, springs 28 and 30, condenser 16, and conductor '61,through the polar relay 102, to the neutral, with a multiple circuitthrough the condenser 107, and the alternating current relay 104 toneutral. Polar relay 102 is not effected by this alternating currentbecause of the copper slugs on the armature ends of the cores ofwindings 102 and 102 but the relay 104 is energized. Relay 104 atsprings 145 opens a circuit of the energizing winding 103 of the polarrelay 102. This polar relay is of the type which magnetically locksitself into the position in which'it was last set, remaining there afterthe current decreases in its coils. The magnetism for locking thearmature 137 and for polarizing the relay is furnished by theelectro-magnet 103. Therefore, when the relay 104 energizes and opensthe circuit of relay 103, the magnetism which holds armature 137 in itsenergized position will die away and the armature will restore to itsmiddle position. In the middle position, springs 135 and 136 both engagetheir break contacts, which contacts are connected together andconnected to the negative pole of the local battery. Relay 101 will notreceive any current, and since it is a relay of the type which restoresto its neutral posi tion when the current is removed from its coils, thearmature 134 assumed a neutral position and closes contacts associatedwith that position.

Thus it will be seen that through one conductor 70, one bank contact ofthe selecting switch, the relay 102 is controlled to assume any one ofits three positions, as result of which the operating relay 101 ispositioned in any one of its three positions.

WVhen the switches S1 and S2 have completed their energizing andenergize the relay 13 in the hereinbefore explained manner, motor magnet15 energizes and energizes the relay 14 which at springs 54 opens acircuit of the conductor 70, thereby removing whatever one of the threepotentials has been applied to the relays 102 and 101. If alternatingcurrent has been applied and relay 104 is energized, it deenergizes andagain closes the circuit of polarizing winding 103. However, since thearmature 137 is in its neutral position, re-application of magnetism tothe relay will not move the armature, and it will remain in thatposition until the coils 102 and 102 are energized in one or the otherdirections. Stepping is resumed and the switches are moved on to theirsixth working bank contacts. In this position wiper 132 again engages anopen contact, and wiper 130 engages contact leading to the polarizedrelays 108 and the alternating current relay 110, which relays jointlycontrol the operating relay 112. If the key K1 is in its normalposition, as shown on the drawings, alternating current will beprojected over the conductor to operate the relay 110 to release thepolar relay 108 to its neutral position. This operation is identicalwith that which has already been explained and will not be repeated. Theswitches take another step, bringing the wiper into engagement with thesupervisory circuit controlled by the track relay 111, andsimultaneously bringing the wiper 36 into engagement with the contact towhich conductor 62 is connected, which contact leads to the supervisorypolar relay 6. \Vhen the track relay is in the position shown in thedrawings and relay 106 is deenergized, circuit may be traced frompositive battery through the resistance 123, conductor 174, spring 146and its break contact, conductor 173, wiper 130. springs 152. conductor70, springs 54, wiper 36, conductor 62, through the winding of relay 6to neutral. Relay 6 energizes over this circuit, at-

tracting the armature 38 to the position shown in the drawings, to closea circuit for the lamp 18, which lights to indicate to the despatcherthat the track relay 11 is in its energized position.

lVhen a train enters the siding across which relay 111 is bridged, thatrelay falls back, springs 127 and 128 move downward against theirlowermost contacts. This operation momentarily breaks the circuit ofrelay 107, permitting that relay to deenergize. The deenergization ofrelay 107 prepares the circuit for starting the switches S, S1, S2,etc.. these circuits being held open elsewhere if the switches are outof their normal position at the moment. The deenergization of track rela111 closes a circuit from neutral to springs 128, and the relay 106 tonegative, energizing the relay 106, which locksitself to springs andsprings 139 to neutral independent of the track relay 111. Thedeenergization of relay 106, alters at springs 146 the circuit justtraced for relay 6, so that instead of wiper 130 picking up positivebattery 'it picks up negative battery and the relay 6 is operated in theopposite direction to move the springs 38 to the left into engagementwith the other set of contacts. This closes a circuit from neutralthrough the armature 38 and at the upper winding of relay 5 negative,energizing relay 5 which lights the signal lamp 19 to indicate to thedespatcher that the track relay 111 is in its deencrgized position.

If the switches are out of their normal position and the wiper 130 doesnot happen to be resting on the contact to which conductor 173 isconnected at the time that the relay 106 energizes, the energization ofrelay 106 produces no instant result. The relay is locked energized, andas soon as the switches get back into their normal position, stepping isagain started over a circuit traceable from neutral through spring 148and its break contact, the winding of relay 105, conductor negative.Relay 10 energizes, again closing the circuit of alarm relay 11 to soundthe bell for an instant to indicate that a supervisory signal is comingin. Relay 10 at springs 49 closes the hereinbeforetraced impulsingcircuit to start stepping of switches over their banks. Relay 105energizes over this circuit, locking itself energized through spring 139and its make contacts independent of the relay contacts 148, and atarmatures 138 re-appli'es negative to the midpoint of relay 107,energizing that relay. Relay 107 upon energizing locks itself to springs147 and its lower winding through springs 127 to neutral, it beingremembered that track relay now is assumed to be deenergized.

111 reenergizes, the

circuit of relay 107 is broken, and that relay falls back to store upanother supervisory signal, and the relays 105, 106, and 107 preparecircuits for starting the stepping switches from their normal positionwhen those switches reach that position. Associated with the relay 6 isa recorder, not shown, which may be any kind of a pen register orprinting recorder whichwill register the time during which the armature38 is resting against its lefthand make contact. Since the armature 38is moved to that position when track relay de energizes by the entranceof the train upon the siding, the record made by the recorder will inthis case be the length of time that that particular siding is occupied;that is, the length of time that a train lays on the, siding.

The switches continue stepping in the same manner as previouslydescribed until the wipers are returned to their normal position. WVhenthe wiper 37 reaches its normal position relay 9 energizes and opens thepulsing circuit to stop further rotation of the switches.

Under certain circumstances the dcspatcher may desire to lock in allsupervisory sig nals, such as 19, to do which he operates key K2 toclose springs 56. It will be, obvious that when the relays, such asrelay 5, are once energized by the movement of armatures 38, they lockthemselves through their lower windings, and will remain in energizedpositions until the despatcher restores key K2 independent of thearmatures 38.

The dispatcher may wish to leave his position for a short time and byoperating the key K2 which is common to all of the supervisory lamps,will know by the condition of the lamps on his return the distance thetrain has travelled and in which block the train is at present located.lVhen the train enters a certain block, the lamp 18 associated therewithis extinguished and lamp 19 is lighted, and when the train leaves thisblock the lamp 18 is again illuminated. and it the key K2 should bethrown at this time then both lamps are illuminated to indicate to thedispatcher on his return that the train has entered this block and haspassed into the next. The dispatcher will know, upon ohserving thecondition of the lamps, just which block the train is in because thelamp 18 associated with this block will not at this time be illuminatedbecause the train is still'in this block.

Having thus described my invention, what I consider new and desire tohave protected by Letters Patent is pointed out in the appended claims.

Vb at is claimed is:

1 In a remote control system, switching mechanism having wipers and bankcontacts accessible thereto, a plurality of three-position polarizedrelays each associated with a certain one of said contacts, an armaturefor each of said relays having three positions, means for operating thewipers of said mechanism to select one of said relays and to place,positive, negative battery or alternating current on the contactassociated with said relay, means responsive thereto for operating thearmature of the relay to one of its three positions in accordance withthe potential placed on its associated contact when the wipers of saidmechanism reach such contact, and means tor maintaining the armature ofsaid relay in the position to which it is operated after the wipers ofsaid mechanism have passed beyond its associated contact.

2. In a remote control system, a plurality of step-by-step switcheshaving wipers, a plurality of three-position relays each having anarmature, a bank contact individual to each of said relays andaccessible to the wiper of the first of said switches, other bankcontacts each correspomling to a contact in the first switch bank andaccessible to the wiper of the second of said switches, a three-positioncontrol key associated with each of said other contacts, meansassociated with each of said keys for placing positive, negative batteryor alternating current on its associated contact dependent upon theposition of said key, means responsiveto an operation of one of saidkeys to any of its three positions for operating said switches to steptheir Wipers to successively engage corresponding contacts in theirrespective banks, circuits completed between said wipers tor each ofsaid relays responsive to the wipers engaging corre sponding contacts inboth switch banks for operating the armatures of some of said relays toone of their tree positions in accordance with the potential on saidother contacts in case the associated key has been operated. and thearmatures on other of said relays remaining in their operated positionsresponsive to said potential in case the associated key has not beenoperated, and means for maintaining the armatures of said relays intheir operated positions after the wipers of said switches have passedtheir corresponding contacts.

3. In a control system, a plurality of three position circuit closers. apair of magnets for each circuit closer, a circuit for each pair of saidmagnets. means for selecting one of said circuits and for connectingalternating current or direct current of different polarity over saidcircuit. said magnets responsive to direct current of one polarity tomove said circuit closer to one position and responsive to directcurrent of another polarity to move said circuit closer to anotherposition, another magnct for each circuit closer, magnetic circuits foreach of said last magnets including its associated circuit closer, meansfor energizing said last magnets to induce a magnetic flux in either oneof their associated magnetic circuits to maintain said associatedcircuit closer in either position, means responsive to alternatingcurrent connected over said circuit for deenergizing the last magnetassociated with said selected circuit, and means responsive to thedeenergization of said last magnet and the dissipation of the magneticflux therein for moving said selected circuit closer to its thirdposition.

4. In a control system, a plurality of relays each comprising threemagnets and an armature having three positions, a circuit for each relayincluding the windings of the first and second magnets in series, aplurality of different kinds of current sources, means for momentarilyselecting one of said circuits and for momentarily connecting saiddifferent sources to said circuit, means for operating the armature ofthe selected relay to its first position in case the first magnet isenergized in response to one kind of current connected to said circuitand for operating said armature to its second position in case thesecond magnet is energized in response to another kind of currentconnected to said circuit, a normally closed circuit individual to eachrelay for energizing the winding of the third magnet, magnetic circuitsfor maintaining the armatures of said relays in the positions to whichthey were last operated when said third magnets are energized over theirindividual normally closed circuits, a second relay associated with eachof said first circuits for individually controlling the normally closedcircuits of the third magnets, means for energizing the associatedsecond relay over said selected circuit in case a third kind of currentsource is connected to said circuit, and contacts on said second relayfor opening the normally closed circuit of the third magnet todeenergize said third magnet to dissiplate the magnetic flux in saidmagnetic circuit to move the armature of the selected relay to its thirdposition. I

5. In a control system, a manually operated key having three positions,two relays associated therewith, a single contact individual to said keyand relays, a plurality of different kinds of current sources, a circuitincluding normally closed contacts on said relays in a series forconnecting one kind of current to said single contact in case said keyis operated to one position, a second circuit for the first relay. meansresponsive to the operation of said key to its second posit-ion forcompleting said second circuit to energize the first relay. meansoperated by the energization of the first relay for connecting anotherkind of current to said single contact and for opening said firstcircuit, a third circuit for the second relay, means responsive to theoperation of said key to its third posi-

